mm/demotion: add hotplug callbacks to handle new numa node onlined

If the new NUMA node onlined doesn't have a abstract distance assigned,
the kernel adds the NUMA node to default memory tier.

[aneesh.kumar@linux.ibm.com: fix kernel error with memory hotplug]
Link: https://lkml.kernel.org/r/20220825092019.379069-1-aneesh.kumar@linux.ibm.com
Link: https://lkml.kernel.org/r/20220818131042.113280-4-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Wei Xu <weixugc@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hesham Almatary <hesham.almatary@huawei.com>
Cc: Jagdish Gediya <jvgediya.oss@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
index 5f24396..7ae6308 100644 (file)
--- a/include/linux/memory-tiers.h
+++ b/include/linux/memory-tiers.h
@@ -14,6 +14,7 @@
  * the same memory tier.
  */
 #define MEMTIER_ADISTANCE_DRAM ((4 * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1))
+#define MEMTIER_HOTPLUG_PRIO   100
 
 #ifdef CONFIG_NUMA
 #include <linux/types.h>

diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index f3dc331..f74e077 100644 (file)
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -5,6 +5,7 @@
 #include <linux/lockdep.h>
 #include <linux/sysfs.h>
 #include <linux/kobject.h>
+#include <linux/memory.h>
 #include <linux/memory-tiers.h>
 
 struct memory_tier {
@@ -105,6 +106,72 @@ static struct memory_tier *set_node_memory_tier(int node)
        return memtier;
 }
 
+static struct memory_tier *__node_get_memory_tier(int node)
+{
+       struct memory_dev_type *memtype;
+
+       memtype = node_memory_types[node];
+       if (memtype && node_isset(node, memtype->nodes))
+               return memtype->memtier;
+       return NULL;
+}
+
+static void destroy_memory_tier(struct memory_tier *memtier)
+{
+       list_del(&memtier->list);
+       kfree(memtier);
+}
+
+static bool clear_node_memory_tier(int node)
+{
+       bool cleared = false;
+       struct memory_tier *memtier;
+
+       memtier = __node_get_memory_tier(node);
+       if (memtier) {
+               struct memory_dev_type *memtype;
+
+               memtype = node_memory_types[node];
+               node_clear(node, memtype->nodes);
+               if (nodes_empty(memtype->nodes)) {
+                       list_del_init(&memtype->tier_sibiling);
+                       memtype->memtier = NULL;
+                       if (list_empty(&memtier->memory_types))
+                               destroy_memory_tier(memtier);
+               }
+               cleared = true;
+       }
+       return cleared;
+}
+
+static int __meminit memtier_hotplug_callback(struct notifier_block *self,
+                                             unsigned long action, void *_arg)
+{
+       struct memory_notify *arg = _arg;
+
+       /*
+        * Only update the node migration order when a node is
+        * changing status, like online->offline.
+        */
+       if (arg->status_change_nid < 0)
+               return notifier_from_errno(0);
+
+       switch (action) {
+       case MEM_OFFLINE:
+               mutex_lock(&memory_tier_lock);
+               clear_node_memory_tier(arg->status_change_nid);
+               mutex_unlock(&memory_tier_lock);
+               break;
+       case MEM_ONLINE:
+               mutex_lock(&memory_tier_lock);
+               set_node_memory_tier(arg->status_change_nid);
+               mutex_unlock(&memory_tier_lock);
+               break;
+       }
+
+       return notifier_from_errno(0);
+}
+
 static int __init memory_tier_init(void)
 {
        int node;
@@ -126,6 +193,7 @@ static int __init memory_tier_init(void)
        }
        mutex_unlock(&memory_tier_lock);
 
+       hotplug_memory_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRIO);
        return 0;
 }
 subsys_initcall(memory_tier_init);